Bioassay Guided Isolation and α-Glucosidase Inhibition Studies of a New Sesquiterpene from Ochradenus aucheri.

AIMS: The aim of the current study was to explore the anti-diabetic potential of Ochradenus aucheri Boiss (O. aucheri). METHOD: All the fractions of O. aucheri were evaluated for α-glucosidase inhibition, followed by bioassay-guided isolation which resulted in a new sesquiterpenoid, as a potential α-glucosidase inhibitor. RESULTS: The preliminary screening showed that all the fractions including n-hexane (38.0 ± 1.38 µg/mL), dichloromethane (92.6 ± 6.18 µg/mL), ethyl acetate (29.2 ± 0.51 µg/mL) and n-butanol (361.8 ± 5.80 µg/mL) displayed significant α-glucosidase inhibitory activity. The activity-directed fractionation and purification of ethyl acetate fraction led to the isolation of one new sesquiterpenoid, Jardenol (1), and two known metabolites: ß-stitosterol-3-O-ß-D-glucopyranoside (2) and ß-Sitosterol (3). To the best of our knowledge, these metabolites have not been isolated from this plant previously. The structure of the new metabolite 1 was confirmed through 1D and 2D NMR spectroscopy, and MS analysis. Compound 1 showed significant α-glucosidase inhibition with an IC50 value of 138.2 ± 2.43 µg/mL as compared to positive control acarbose (IC50 = 942.0 ± 0.60 µg/mL). Additionally, in-silico docking was employed to predict the binding mechanism of compound 1 in the active site of the target enzyme, α-glucosidase. The docking results suggested that the compound forms strong interactions at the catalytic site of α-glucosidase. CONCLUSION: The results of the present study indicated that the newly purified secondary metabolite, Jardenol, can be a promising anti-diabetic compound.

Synthesis of 2,4-Bis(trifluoromethyl)benzaldehyde Hybrid Thiosemicarbazones as Prolyl Oligopeptidase Inhibitors for Neurodegenerative Disorders and their In-silico Analysis.

INTRODUCTION: Prolyl-specific oligopeptidase (POP), one of the brain's highly expressed enzymes, is an important target for the therapy of central nervous system disorders, notably autism spectrum disorder, schizophrenia, Parkinson's, Alzheimer's disease, and dementia. METHOD: The current study was designed to investigate 2,4-bis(trifluoromethyl) benzaldehyde- based thiosemicarbazones as POP inhibitors to treat the above-mentioned disorders. A variety of techniques, such as nuclear magnetic resonance (NMR), mass spectrometry (MS), and Fourier-transform infrared spectroscopy (FTIR), were used for the structural confirmation of synthesized compounds. After in-vitro evaluation, all of these compounds were found to be prominent inhibitors of the POP enzyme (IC50= 10.14 - 41.73 µM). RESULT: Compound 3a emerged as the most active compound (IC50 10.14 ± 0.72 µM) of the series. The kinetic study of the most active 3a (Ki =13.66 0.0012 µM) indicated competitive inhibition of the aforementioned enzyme. CONCLUSION: Moreover, molecular docking depicted a noticeable role of thiosemicarbazide moiety in the binding of these molecules within the active site of the POP enzyme.

Synthesis of novel 1,2,3-triazole-tethered N-acyl hydrazones as a new class of carbonic anhydrase II inhibitors: In vitro and in silico potentials.

Carbonic anhydrase II (CA II) is crucial for maintaining homeostasis in several processes, including respiration, lipogenesis, gluconeogenesis, calcification, bone resorption, and electrolyte balance. It is a pivotal druggable target which is implicated in glaucoma, renal, gastric, and pancreatic carcinomas, as well as in malignant brain tumours. Therefore, to identify new CA II (bovine) inhibitors, the current study was designed to synthesize a library of 20 new triazole-linked hydrazones (6a-t). All compounds were characterized by using spectroscopic techniques such as NMR and mass spectrometry. The in-vitro evaluation resulted in impressive inhibitory capability against CA II with IC50 values ranging from 9.10 ± 0.26-48.26 ± 1.30 µM. Among all derivatives, compounds 6a, 6b, 6d, 6k-6m, 6q, 6s and 6t exhibited potent inhibitory potential with 6t deemed as the most active inhibitor. Additionally, kinetic study of the hybrid 6t revealed concentration dependent type of inhibition with Ki value 7.24 ± 0.0086 µM. Furthermore, molecular docking of 6t correlates well with the kinetic analysis. The in-silico ADMET indicated that most of the synthesized compounds have properties conducive to drug development.

Synthesis, in vitro and in silico study of novel 1,3-diphenylurea derived Schiff bases as competitive α-glucosidase inhibitors.

Diabetes mellitus has become a major global health burden because of several related consequences, including heart disease, retinopathy, cataracts, metabolic syndrome, collapsed renal function, and blindness. In the recent study, thirty Schiff base derivatives of 1,3-diphenylurea were synthesized and their anti-diabetic activity was evaluated by targeting α-glucosidase. The compounds exhibited an overwhelming inhibitory potential for α-glucosidase with higher potency ranging from 2.49-37.16 µM. The most effective compound, 5h, showed competitive inhibition of α-glucosidase (K i = 3.96 ± 0.0048 µM) in the kinetic analysis and strong binding interactions with key residues α-glucosidase in docking analysis, indicating its potential for better glycemic control in diabetes patients.

Morpholine-tethered Novel Hydrazones as Promising Non-peptidic Prolyl Oligopeptidase (POP) Inhibitors: Synthesis In Vitro and In Silico Studies.

INTRODUCTION: Prolyl oligopeptidase (POP) is a pivotal druggable target implicated in diverse biological processes and linked to the development of various ailments, including neurodegenerative disorders. While conventional peptide-based inhibitors have been a centerpiece, their limitations, such as restricted bioavailability, necessitate exploration of non-peptidic inhibitors for their therapeutic potential. METHOD: This study focuses on designing, synthesizing, and assessing morpholine-based hydrazones targeting the catalytic serine residue of POP. The hydrazones (5a-o), reported as moderately potent analogs compared to the renowned Z-Pro-Prolinal, demonstrated in vitro POP inhibition with IC50 values ranging from 13.60 ± 2.51 to 36.51 ± 1.82 µM. The derivative 5h, with an IC50 of 13.60 ± 2.51 µM, emerged as the most potent inhibitor. RESULTS: Moreover, the in vitro kinetic study of compound 5h indicated that it exhibited concentration-dependent type of inhibition. in silico docking studies of 5h revealed robust interactions in the POP enzyme's active site, yielding a docking score of -6.30 Kcal/- mol, consistent with experimental results. CONCLUSION: All findings underscored the potential of synthesized derivatives for drug development.

Exploring the Therapeutic Potential of Coumarin-thiazolotriazole Pharmacophores for SARS-CoV-2 Spike Protein through In-vitro and In-silico Evaluation.

INTRODUCTION: The pandemic caused by SARS-CoV-2 significantly impacted human life around the globe. Numerous unexpected modifications of the SARS-CoV-2 genome have resulted in the emergence of new types and have caused great concern globally. METHOD: Inhibitory effects of bioactive phytochemicals derived from natural and synthetic sources are promising for pathogenic viruses. in vitro and in silico techniques were used in the current study to identify novel inhibitors of coumarin clubbed thiazolo[3,2-b][1,2,4]triazoles against the SARS-CoV-2 spike protein. RESULT: Interestingly, all the tested molecules demonstrated substantial inhibition of spike protein with 91.81-57.90% inhibition. The spike protein was remarkably inhibited by compounds 6k (91.83%), 6j (89.75%), 6m (87.69%),6i (86.60%), 6l (85.40%), 6h (84.70%), 6l (84.70%), 6g (83.40%), 6b (82.60%), 6f (81.90%), while compounds 6d 6a, 6c, and 6e exhibited significant activity against spike protein with 79.60%, 77.10%, 75.30%, and 57.90% inhibition, respectively. The binding mechanism of these novel inhibitors with spike protein was deduced in silico, which reflects that the active molecules firmly bind with the receptor binding domain (RBD) of spike protein, thereby inhibiting its function. CONCLUSION: The combined in vitro and in silico investigations unfold the therapeutic potential of coumarin-thiazolotriazole scaffolds in the treatment of SARS-CoV-2 infection.

Disrupting protease and deubiquitinase activities of SARS-CoV-2 papain-like protease by natural and synthetic products discovered through multiple computational and biochemical approaches.

The single-stranded RNA genome of SARS-CoV-2 encodes several structural and non-structural proteins, among which the papain-like protease (PLpro) is crucial for viral replication and immune evasion and has emerged as a promising therapeutic target. The current study aims to discover new inhibitors of PLpro that can simultaneously disrupt its protease and deubiquitinase activities. Using multiple computational approaches, six compounds (CP1-CP6) were selected from our in-house compounds database, with higher docking scores (-7.97 kcal/mol to -8.14 kcal/mol) and fitted well in the active pocket of PLpro. Furthermore, utilizing microscale molecular dynamics simulations (MD), the dynamic behavior of selected compounds was studied. Those molecules strongly binds at the PLpro active site and forms stable complexes. The dynamic motions suggest that the binding of CP1-CP6 brought the protein to a closed conformational state, thereby altering its normal function. In an in vitro evaluation, CP2 showed the most significant inhibitory potential for PLpro (protease activity = 2.71 ± 0.33 µM and deubiquitinase activity = 3.11 ± 0.75 µM), followed by CP1, CP5, CP4 and CP6. Additionally, CP1-CP6 showed no cytotoxicity at a concentration of 30 µM in the human BJ cell line.

Corrigendum to "Antimicrobial topical polymeric films loaded with Acetyl-11-keto-ß-boswellic acid (AKBA), boswellic acid and silver nanoparticles: Optimization, characterization, and biological activity" [Heliyon 10(11) 15th June 2024, e31671].

[This corrects the article DOI: 10.1016/j.heliyon.2024.e31671.].

Phytoconstituents with cardioprotective properties: A pharmacological overview on their efficacy against myocardial infarction.

Myocardial infarction (MI) is considered one of the most common cardiac diseases and major cause of death worldwide. The prevalence of MI and MI-associated mortality have been increasing in recent years due to poor lifestyle habits viz. residency, obesity, stress, and pollution. Synthetic drugs for the treatment of MI provide good chance of survival; however, the demand to search more safe, effective, and natural drugs is increasing. Plants provide fruitful sources for powerful antioxidant and anti-inflammatory agents for prevention and/or treatment of MI. However, many plant extracts lack exact information about their possible dosage, toxicity and drug interactions which may hinder their usefulness as potential treatment options. Phytoconstituents play cardioprotective role by either acting as a prophylactic or adjuvant therapy to the concurrently used synthetic drugs to decrease the dosage or relief the side effects of such drugs. This review highlights the role of different herbal formulations, examples of plant extracts and types of several isolated phytoconstituents (phenolic acids, flavonoids, stilbenes, alkaloids, phenyl propanoids) in the prevention of MI with reported activities. Moreover, their possible mechanisms of action are also discussed to guide future research for the development of safer substitutes to manage MI.

Antimicrobial topical polymeric films loaded with Acetyl-11-keto-ß-boswellic acid (AKBA), boswellic acid and silver nanoparticles: Optimization, characterization, and biological activity.

The study examined the antimicrobial and antioxidant potential of pure Acetyl-11-keto-ß-boswellic acid (AKBA), boswellic acid (70%) and AKBA loaded nanoparticles as topical polymeric films. The optimized concentration (0.05 % w/v) of pure AKBA, boswellic acid (BA), and AKBA loaded silver nanoparticles were used to study its impact on film characteristics. Carboxymethyl cellulose (CMC), sodium alginate (SA), and gelatin (Ge) composite films were prepared in this study. The polymeric films were evaluated for their biological (antioxidant and antimicrobial activities) and mechanical characteristics such as tensile strength (TS) and elongation (%). Moreover, other parameters including water barrier properties and color attributes of the film were also evaluated. Furthermore, assessments were conducted using analytical techniques like FTIR, XRD, and SEM. Surface analysis revealed that AgNP precipitation led to a few particles in the film structure. Overall, the results indicate a relatively consistent microstructure. Moreover, due to the addition of AKBA, BA, and AgNPs, a significant decrease in TS, moisture content, water solubility, and water vapor permeation was observed. The films transparency also showed a decreasing trend, and the color analysis revealed decreasing yellowness (b*) of the films. Importantly, a significant increase in antioxidant activity against DPPH free radicals and ABTS cations was observed in the CSG films. Additionally, the AgNP-AKBA loaded films displayed significant antifungal activity against C. albicans. Moreover, the molecular docking analysis revealed the inter-molecular interactions between the AKBA, AgNPs, and composite films. The docking results indicate good binding of AKBA and silver nanoparticles with gelatin and carboxymethyl cellulosemolecules. In conclusion, these polymeric films have potential as novel materials with significant antioxidant and antifungal activities.

Identification of small molecular inhibitors of SIRT3 by computational and biochemical approaches a potential target of breast cancer.

Sirtuin 3 (SIRT3) belongs to the Sirtuin protein family, which consists of NAD+-dependent lysine deacylase, involved in the regulation of various cellular activities. Dysregulation of SIRT3 activity has been linked to several types of cancer, including breast cancer. Because of its ability to stimulate adaptive metabolic pathways, it can aid in the survival and proliferation of breast cancer cells. Finding new chemical compounds targeted towards SIRT3 was the primary goal of the current investigation. Virtual screening of ~ 800 compounds using molecular docking techniques yielded 8 active hits with favorable binding affinities and poses. Docking studies verified that the final eight compounds formed stable contacts with the catalytic domain of SIRT3. Those compounds have good pharmacokinetic/dynamic properties and gastrointestinal absorption. Based on excellent pharmacokinetic and pharmacodynamic properties, two compounds (MI-44 and MI-217) were subjected to MD simulation. Upon drug interaction, molecular dynamics simulations demonstrate mild alterations in the structure of proteins and stability. Binding free energy calculations revealed that compounds MI-44 (- 45.61 ± 0.064 kcal/mol) and MI-217 (- 41.65 ± 0.089 kcal/mol) showed the maximum energy, suggesting an intense preference for the SIRT3 catalytic site for attachment. The in-vitro MTT assay on breast cancer cell line (MDA-MB-231) and an apoptotic assay for these potential compounds (MI-44/MI-217) was also performed, with flow cytometry to determine the compound's ability to cause apoptosis in breast cancer cells. The percentage of apoptotic cells (including early and late apoptotic cells) increased from 1.94% in control to 79.37% for MI-44 and 85.37% for MI-217 at 15 µM. Apoptotic cell death was effectively induced by these two compounds in a flow cytometry assay indicating them as a good inhibitor of human SIRT3. Based on our findings, MI-44 and MI-217 merit additional investigation as possible breast cancer therapeutics.

Structural, dynamic behaviour, in-vitro and computational investigations of Schiff's bases of 1,3-diphenyl urea derivatives against SARS-CoV-2 spike protein.

The COVID-19 has had a significant influence on people's lives across the world. The viral genome has undergone numerous unanticipated changes that have given rise to new varieties, raising alarm on a global scale. Bioactive phytochemicals derived from nature and synthetic sources possess lot of potential as pathogenic virus inhibitors. The goal of the recent study is to report new inhibitors of Schiff bases of 1,3-dipheny urea derivatives against SARS COV-2 spike protein through in-vitro and in-silico approach. Total 14 compounds were evaluated, surprisingly, all the compounds showed strong inhibition with inhibitory values between 79.60% and 96.00% inhibition. Here, compounds 3a (96.00%), 3d (89.60%), 3e (84.30%), 3f (86.20%), 3g (88.30%), 3h (86.80%), 3k (82.10%), 3l (90.10%), 3m (93.49%), 3n (85.64%), and 3o (81.79%) exhibited high inhibitory potential against SARS COV-2 spike protein. While 3c also showed significant inhibitory potential with 79.60% inhibition. The molecular docking of these compounds revealed excellent fitting of molecules in the spike protein receptor binding domain (RBD) with good interactions with the key residues of RBD and docking scores ranging from - 4.73 to - 5.60 kcal/mol. Furthermore, molecular dynamics simulation for 150 ns indicated a strong stability of a complex 3a:6MOJ. These findings obtained from the in-vitro and in-silico study reflect higher potency of the Schiff bases of 1,3-diphenyl urea derivatives. Furthermore, also highlight their medicinal importance for the treatment of SARS COV-2 infection. Therefore, these small molecules could be a possible drug candidate.

One pot synthesis of 5-hydroxyalkylated thiadiazine thiones: Implication in pain management and bactericidal properties.

The synthesis of a new series of thiadiazine thiones including 5-(2-hydroxyethyl)-3-alkyl/aryl-1, 3, 5-thiadiazine-2-thiones (1-5), 5-(2-hydroxypropyl)-3-alkyl/aryl-1, 3, 5-thiadiazine-2-thiones (6-8), 3,5-dipropyl-1, 3, 5-thiadiazine-2-thione (9) and (2-(5-alkyl/aryl-6-thioxo-1, 3, 5-thiadiazine-3-yl) alkyl acetate/benzoate) (10-17) was accomplished via one pot reaction. The structures of the synthesized compounds were characterized through NMR and Mass spectrometry. The anti-nociceptive activity of compounds was performed on BALB/C mice by hot plate method, where compounds 3, 5 (50 µg/kg), and 8 (50, 100 µg/kg) exhibited significant effect (P < 0.01, P < 0.05) in latency time of 15, 30, and 60 min, while compounds 6 and 16 (100 µg/kg) exhibited significant effect (P < 0.01, P < 0.05) in latency time interval of 15 and 30 min. Compounds 1, 12-13, and 15 showed moderate activity. Among the tested hits, compounds 5 (17.3 ± 2.2), 11 (16.2 ± 2.1), and 8 (16.1 ± 2.1) showed significant anti-nociceptive potential. Molecular docking studies on the most active anti-nociceptive hits indicated that the activity might be attributed to the ability of the compounds to target µ-opioid receptor (µOR) effectively. Furthermore, compounds 14 and 11 showed anti-bacterial activity against Pseudomonas aeruginosa and MSRA with MIC of 40.97 and 54.77 µg/mL, respectively. In addition, the predicted ADMET profile of 5, 9, and 11 indicates that these molecules follow the drug-likeness criteria, and their activity can be enhanced through structural optimization.

Muscle relaxant and antipyretic effects of pentacyclic triterpenes isolated from the roots of Diospyros lotus L.

The present article describes the muscle relaxant and antipyretic effects of pentacyclic triterpenes, oleanolic acid (OA), ursolic acid (UA) and betulinic acid (BA) isolated from roots of Diospyros lotus in animal models. The muscle relaxant effects of isolated pentacyclic triterpenes were determined by chimney and inclined plane tests. In the chimney test, pretreatment of pentacyclic triterpenes evoked significant dose dependent influence on muscle coordination. When administered intraperitoneally (i.p.) to mice at 10 mg/kg for 90 min, OA, UA, and BA exhibited muscle relaxant effects of 66.72 %, 60.21 %, and 50.77 %, respectively. Similarly, OA, UA, and BA (at 10 mg/kg) illustrated 65.74 %, 59.84 % and 51.40 % muscle relaxant effects in the inclined plane test. In the antipyretic test, significant amelioration was caused by pretreatment of all compounds in dose dependent manner. OA, UA, and BA (at 5 mg/kg) showed 39.32 %, 34.32 % and 29.99 % anti-hyperthermic effects, respectively 4 h post-treatment, while at 10 mg/kg, OA, UA, and BA exhibited 71.59 %, 60.99 % and 52.44 % impact, respectively. The muscle relaxant effect of benzodiazepines is well known for enhancement of GABA receptors. There may exist a similar mechanism for muscle relaxant effect of pentacyclic triterpenes. The in-silico predicted binding pattern of all the compounds reflects good affinity of compounds with GABAA receptor and COX-2. These results indicate that the muscle relaxant and antipyretic activities of these molecules can be further improved by structural optimization.

Novel Natural Inhibitors for Glioblastoma by Targeting Epidermal Growth Factor Receptor and Phosphoinositide 3-kinase.

BACKGROUND/AIM: Glioblastoma is an extensively malignant neoplasm of the brain that predominantly impacts the human population. To address the challenge of glioblastoma, herein, we have searched for new drug-like candidates by extensive computational and biochemical investigations. METHODS: Approximately 950 compounds were virtually screened against the two most promising targets of glioblastoma, i.e., epidermal growth factor receptor (EGFR) and phosphoinositide 3-kinase (PI3K). Based on highly negative docking scores, excellent binding capabilities and good pharmacokinetic properties, eight and seven compounds were selected for EGFR and PI3K, respectively. RESULTS: Among those hits, four natural products (SBEH-40, QUER, QTME-12, and HCFR) exerted dual inhibitory effects on EGFR and PI3K in our in-silico analysis; therefore, their capacity to suppress the cell proliferation was assessed in U87 cell line (type of glioma cell line). The compounds SBEH-40, QUER, and QTME-12 exhibited significant anti-proliferative capability with IC50 values of 11.97 ± 0.73 µM, 28.27 ± 1.52 µM, and 22.93 ± 1.63 µM respectively, while HCFR displayed weak inhibitory potency (IC50 = 74.97 ± 2.30 µM). CONCLUSION: This study has identified novel natural products that inhibit the progression of glioblastoma; however, further examinations of these molecules are required in animal and tissue models to better understand their downstream targeting mechanisms.

Synthesis of hydrazone-based polyhydroquinoline derivatives - antibacterial activities, α-glucosidase inhibitory capability, and DFT study.

In recent years, polyhydroquinolines have gained much attention due to their widespread applications in medicine, agriculture, industry, etc. Here, we synthesized a series of novel hydrazone-based polyhydroquinoline derivatives via multi-step reactions. These molecules were characterized by modern spectroscopic techniques (1H-NMR, 13C NMR, and LC-HRMS) and their antibacterial and in vitro α-glucosidase inhibitory activities were assessed. Compound 8 was found to be the most active inhibitor against Listeria monocytogenes NCTC 5348, Bacillus subtilis IM 622, Brevibacillus brevis, and Bacillus subtilis ATCC 6337 with a zone of inhibition of 15.3 ± 0.01, 13.2 ± 0.2, 13.1 ± 0.1, and 12.6 ± 0.3 mm, respectively. Likewise, compound 8 also exhibited the most potent inhibitory potential for α-glucosidase (IC50 = 5.31 ± 0.25 µM) in vitro, followed by compounds 10 (IC50 = 6.70 ± 0.38 µM), and 12 (IC50 = 6.51 ± 0.37 µM). Furthermore, molecular docking and DFT analysis of these compounds showed good agreement with experimental work and the nonlinear optical properties calculated here indicate that these compounds are good candidates for nonlinear optics.

Biochemical and computational inhibition of α-glucosidase by novel metronidazole-linked 1H-1,2,3-triazole and carboxylate moieties: kinetics and dynamic investigations.

In the current study, metronidazole derivatives containing 1H-1,2,3-triazole and carboxylate moieties were evaluated in vitro and by computational methods for their anti-diabetic potential to insight into their medicinal use for the management of type II diabetes mellitus. Interestingly all 14 compounds displayed high to significant inhibitory capability against the key carbohydrate's digestive enzyme α-glucosidase with IC50 values in range of 9.73-56.39 µM, as compared to marketed drug acarbose (IC50 = 873.34 ± 1.67 µM). Compounds 5i and 7c exhibited the highest inhibition, therefore, these two compounds were further evaluated for their mechanistic studies to explore its type of inhibition. Compounds 5i and 7c both displayed a concentration-dependent (competitive type of inhibition) with Ki values 7.14 ± 0.01, 6.15 ± 0.02 µM, respectively, which conclude their favourable interactions with the active site residues of the α-glucosidase. Interestingly all compounds are non-cytotoxic against BJ cell line. To further validate our findings, in-silico approaches like molecular docking, and molecular dynamic simulations were applied to investigate the mode of bindings of compounds with the enzyme and identifies their inhibition mechanism, which strongly complements our experimental findings.Communicated by Ramaswamy H. Sarma.

The physicochemical properties and molecular docking study of plasticized amphotericin B loaded sodium alginate, carboxymethyl cellulose, and gelatin-based films.

Plasticizers are employed to stabilize films by safeguarding their physical stability and avoiding the degradation of the loaded therapeutic drug during processing and storage. In the present study, the plasticizer effect (glycerol) was studied on bioadhesive films based on sodium alginate (SA), carboxymethyl cellulose (CMC) and gelatin (GE) polymers loaded with amphotericin B (AmB). The main objective of the current study was to assess the morphological, mechanical, thermal, optical, and barrier properties of the films as a function of glycerol (Gly) concentration (0.5-1.5 %) using different techniques such as Scanning Electron Microscope (SEM), Texture analyzer (TA), Differential Scanning Calorimeter (DSC), X-Ray Diffraction (XRD), and Fourier Transforms Infrared Spectroscopy (FTIR). The concentration increase of glycerol resulted in an increase in Water Vapor Permeability (WVP) (0.187-0.334), elongation at break (EAB) (0.88-35.48 %), thickness (0.032-0.065 mm) and moisture level (17.5-41.76 %) whereas opacity, tensile strength (TS) (16.81-0.86 MPa), and young's modulus (YM) (0.194-0.002 MPa) values decreased. Glycerol incorporation in the film-Forming solution decreased the brittleness and fragility of the films. Fourier Transform Infrared (FTIR) spectra showed that intermolecular hydrogen bonding occurred between glycerol and polymers in plasticized films compared to control films. Furthermore, molecular docking was applied to predict the binding interactions betweem AmB, CMC, gelatin, SA and glycerol, which further endorsed the stabilizing effects of glycerol in the complex formation between AmB, CMC, SA, and gelatin. The Findings of the current study demonstrated that this polymeric blend could be used to successfully prepare bioadhesive films with glycerol as a plasticizer.

Novel hydrazone schiff's base derivatives of polyhydroquinoline: synthesis, in vitro prolyl oligopeptidase inhibitory activity and their Molecular docking study.

This research work reports the synthesis of new derivatives of the hydrazone Schiff bases (1-17) based on polyhydroquinoline nucleus through multistep reactions. HR-ESIMS,1H- and 13C-NMR spectroscopy were used to structurally infer all of the synthesized compounds and lastly evaluated for prolyl oligopeptidase inhibitory activity. All the prepared products displayed good to excellent inhibitory activity when compared with standard z-prolyl-prolinal. Three derivatives 3, 15 and 14 showed excellent inhibition with IC50 values 3.21 ± 0.15 to 5.67 ± 0.18 µM, while the remaining 12 compounds showed significant activity. Docking studies indicated a good correlation with the biochemical potency of compounds estimated in the in-vitro test and showed the potency of compounds 3, 15 and 14. The MD simulation results confirmed the stability of the most potent inhibitors 3, 15 and 14 at 250 ns using the parameters RMSD, RMSF, Rg and number of hydrogen bonds. The RMSD values indicate the stability of the protein backbone in complex with the inhibitors over the simulation time. The RMSF values of the binding site residues indicate that the potent inhibitors contributed to stabilizing these regions of the protein, through formed stable interactions with the protein. The Rg. analysis assesses the overall size and compactness of the complexes. The maintenance of stable hydrogen bonds suggests the existence of favorable binding interactions. SASA analysis suggests that they maintained stable conformations without large-scale exposure to the solvent. These results indicate that the ligand-protein interactions are stable and could be exploited to design new drugs for disease treatment.Communicated by Ramaswamy H. Sarma.

Identification of new pharmacophore against SARS-CoV-2 spike protein by multi-fold computational and biochemical techniques.

COVID-19 appeared as a highly contagious disease after its outbreak in December 2019 by the virus, named SARS-CoV-2. The threat, which originated in Wuhan, China, swiftly became an international emergency. Among different genomic products, spike protein of virus plays a crucial role in the initiation of the infection by binding to the human lung cells, therefore, SARS-CoV-2's spike protein is a promising therapeutic target. Using a combination of a structure-based virtual screening and biochemical assay, this study seeks possible therapeutic candidates that specifically target the viral spike protein. A database of ~ 850 naturally derived compounds was screened against SARS-CoV-2 spike protein to find natural inhibitors. Using virtual screening and inhibitory experiments, we identified acetyl 11-keto-boswellic acid (AKBA) as a promising molecule for spike protein, which encouraged us to scan the rest of AKBA derivatives in our in-house database via 2D-similarity searching. Later 19 compounds with > 85% similarity with AKBA were selected and docked with receptor binding domain (RBD) of spike protein. Those hits declared significant interactions at the RBD interface, best possess and excellent drug-likeness and pharmacokinetics properties with high gastrointestinal absorption (GIA) without toxicity and allergenicity. Our in-silico observations were eventually validated by in vitro bioassay, interestingly, 10 compounds (A3, A4, C3, C6A, C6B, C6C, C6E, C6H, C6I, and C6J) displayed significant inhibitory ability with good percent inhibition (range: > 72-90). The compounds C3 (90.00%), C6E (91.00%), C6C (87.20%), and C6D (86.23%) demonstrated excellent anti-SARS CoV-2 spike protein activities. The docking interaction of high percent inhibition of inhibitor compounds C3 and C6E was confirmed by MD Simulation. In the molecular dynamics simulation, we observed the stable dynamics of spike protein inhibitor complexes and the influence of inhibitor binding on the protein's conformational arrangements. The binding free energy ΔGTOTAL of C3 (-38.0 ± 0.08 kcal/mol) and C6E (-41.98 ± 0.08 kcal/mol) respectively indicate a strong binding affinity to Spike protein active pocket. These findings demonstrate that these molecules particularly inhibit the function of spike protein and, therefore have the potential to be evaluated as drug candidates against SARS-CoV-2.